The invention relates to medical devices, namely to the devices applied in endovascular surgery and interventional cardiology for recovery of narrowed bifurcated sections of a vessel lumen, in particular, in a side branch of the coronary arteries or in the carotid arteries bifurcation.
Fixing a stent in arteries in a bifurcated zone, especially in coronary arteries, constitutes one of the main problems of endovascular surgery and of interventional cardiology in particular. At the present moment, stent techniques, where a stent is implanted into the basic artery are rather common. An additional wire is introduced in a lateral branch through a mesh of the stent and the final angiographic result of the operation is achieved after the balloon angioplasty of the bifurcated zone by two “kissing” balloons. Stenting of bifurcated lesions of arteries is also performed by two stents simultaneously (using techniques: such as cullotte, crush, V-stenting, T-stenting), which represents a high risk of a damage of the arterial wall, a high risk of restenosis and intra-operational technical difficulties. Full optimization of the diameter of an artery in a bifurcated zone by using conventional stents is a difficult problem. There are some designs of special bifurcation stents (for example, the Multi-Link Frontier Stent from Guidant) where the technical result is achieved due to two balloons and two wires on which the stents are clipped and which are positioned both in the basic artery and in a lateral branch. Another type of bifurcation stents has a special mesh structure which has the aperture for a lateral branch (SLK-View™ stent, Advanced Stent Technologies), that allows optimizing implantation of the second stent in a lateral branch. In clinical practice, a Nitinol bifurcation stent by AXXESS Plus, Devax, Inc. is commonly used. The stent is designed in the shape of a frustum, thus, the basic advantage of this stent is the lower probability of shifting plaque masses in a lateral branch during stenting the basic artery. At the same time, all bifurcation stents used today in the clinical practice, have design which, to certain extent, ensures stenting the basic artery and reinforcement of an ostium of a lateral branch, but they do not provide full covering along a lateral branch. These stents have, as a rule, a rather complicated design and the restricted spectrum of application.
From the Russian Patent RU2192810, a set of tools for transluminal insertion of a tubular stent, including self-expandable tubular stent which serves as a transplant, and a device for introduction of the stent, are known. The tool set does not solve the problem of high precision installation of the stent in an ostium of a lateral arterial branch.
An eccentric stent for implantation in a lateral arterial branch is known; it is expanded by means of a balloon catheter (see laid open U.S. Patent Publication No. 2004/0186560). The design of the above stent is adapted for implantation in an ostium segment of a lateral branch of a coronary artery. However, the system of radioactive labels used in this design, does not provide for accurate positioning of the truncated part of the stent in the ostium of the arterial segment that can essentially reduce the safety standard of endovascular operations.
Another solution is presented in Russian patent RU2121317. In this solution the self-recovering stent with delivery system for its implantation in the blood vessel, composing an implantation system, including self-expandable bifurcation stent marked by radioactive labels and made of a wire shaping a cylindrical mesh which material has the shape memory, and the delivery system for implantation of the self-expandable bifurcation stent, containing a polymeric tubular catheter with a polymeric cap at the distal end, a guiding wire and a pushing wire, is described. Though this system has the orientation agents in the form of the radioactive labels located on the stent, the extremely close disposition of labels seriously hampers the accurate orientation by the clipped labels.